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<FONT color="green">001</FONT>    package org.codemonkey.javareflection;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import java.io.DataInputStream;<a name="line.3"></a>
<FONT color="green">004</FONT>    import java.io.File;<a name="line.4"></a>
<FONT color="green">005</FONT>    import java.io.FileInputStream;<a name="line.5"></a>
<FONT color="green">006</FONT>    import java.io.FileNotFoundException;<a name="line.6"></a>
<FONT color="green">007</FONT>    import java.io.IOException;<a name="line.7"></a>
<FONT color="green">008</FONT>    import java.util.HashMap;<a name="line.8"></a>
<FONT color="green">009</FONT>    import java.util.Map;<a name="line.9"></a>
<FONT color="green">010</FONT>    <a name="line.10"></a>
<FONT color="green">011</FONT>    import javax.script.ScriptException;<a name="line.11"></a>
<FONT color="green">012</FONT>    <a name="line.12"></a>
<FONT color="green">013</FONT>    /**<a name="line.13"></a>
<FONT color="green">014</FONT>     * A toolkit that can read and compile .java sourcefiles on the fly in runtime. This &lt;code&gt;class loader&lt;/code&gt; caches loaded classes for<a name="line.14"></a>
<FONT color="green">015</FONT>     * repeated requests. Also, if a .class file already exists for a specific .java sourcefile, the classloader will compare dates and see if<a name="line.15"></a>
<FONT color="green">016</FONT>     * the .java needs recompiling. &lt;br /&gt;<a name="line.16"></a>
<FONT color="green">017</FONT>     * &lt;br /&gt;<a name="line.17"></a>
<FONT color="green">018</FONT>     * A basepath can be specified for the classloader to look in for sourcefiles.<a name="line.18"></a>
<FONT color="green">019</FONT>     */<a name="line.19"></a>
<FONT color="green">020</FONT>    public final class ExternalClassLoader extends ClassLoader {<a name="line.20"></a>
<FONT color="green">021</FONT>            /**<a name="line.21"></a>
<FONT color="green">022</FONT>             * base path used to locate [packaged] classes in<a name="line.22"></a>
<FONT color="green">023</FONT>             */<a name="line.23"></a>
<FONT color="green">024</FONT>            private String basepath;<a name="line.24"></a>
<FONT color="green">025</FONT>    <a name="line.25"></a>
<FONT color="green">026</FONT>            /**<a name="line.26"></a>
<FONT color="green">027</FONT>             * List of classes. These are non-instances of a class, of which instances can be spawn.<a name="line.27"></a>
<FONT color="green">028</FONT>             */<a name="line.28"></a>
<FONT color="green">029</FONT>            protected final Map&lt;String, Class&lt;?&gt;&gt; classes;<a name="line.29"></a>
<FONT color="green">030</FONT>    <a name="line.30"></a>
<FONT color="green">031</FONT>            /**<a name="line.31"></a>
<FONT color="green">032</FONT>             * The exception that was thrown when the class was actually found but some other error occurred.<a name="line.32"></a>
<FONT color="green">033</FONT>             */<a name="line.33"></a>
<FONT color="green">034</FONT>            protected CompileException exception;<a name="line.34"></a>
<FONT color="green">035</FONT>    <a name="line.35"></a>
<FONT color="green">036</FONT>            /**<a name="line.36"></a>
<FONT color="green">037</FONT>             * Constructor which initializes all properties.<a name="line.37"></a>
<FONT color="green">038</FONT>             */<a name="line.38"></a>
<FONT color="green">039</FONT>            public ExternalClassLoader() {<a name="line.39"></a>
<FONT color="green">040</FONT>                    super(ExternalClassLoader.class.getClassLoader());<a name="line.40"></a>
<FONT color="green">041</FONT>                    classes = new HashMap&lt;String, Class&lt;?&gt;&gt;();<a name="line.41"></a>
<FONT color="green">042</FONT>            }<a name="line.42"></a>
<FONT color="green">043</FONT>    <a name="line.43"></a>
<FONT color="green">044</FONT>            /**<a name="line.44"></a>
<FONT color="green">045</FONT>             * Loads a class from the classes cache if available. Delegates to {@link #findClass(String)} otherwise.<a name="line.45"></a>
<FONT color="green">046</FONT>             * <a name="line.46"></a>
<FONT color="green">047</FONT>             * @see ClassLoader#loadClass(String)<a name="line.47"></a>
<FONT color="green">048</FONT>             */<a name="line.48"></a>
<FONT color="green">049</FONT>            @Override<a name="line.49"></a>
<FONT color="green">050</FONT>            public final Class&lt;?&gt; loadClass(final String className)<a name="line.50"></a>
<FONT color="green">051</FONT>                            throws ClassNotFoundException {<a name="line.51"></a>
<FONT color="green">052</FONT>                    final Class&lt;?&gt; c = classes.get(className);<a name="line.52"></a>
<FONT color="green">053</FONT>                    return (c != null) ? c : findClass(className);<a name="line.53"></a>
<FONT color="green">054</FONT>            }<a name="line.54"></a>
<FONT color="green">055</FONT>    <a name="line.55"></a>
<FONT color="green">056</FONT>            /**<a name="line.56"></a>
<FONT color="green">057</FONT>             * Loads a classfile from file in the following order:<a name="line.57"></a>
<FONT color="green">058</FONT>             * &lt;ol&gt;<a name="line.58"></a>
<FONT color="green">059</FONT>             * &lt;li&gt;looks for the java source and if available, checks whether it needs to be compiled&lt;/li&gt;<a name="line.59"></a>
<FONT color="green">060</FONT>             * &lt;li&gt;if no .java or .class file found, try to find it in the VM&lt;/li&gt;<a name="line.60"></a>
<FONT color="green">061</FONT>             * &lt;/ol&gt;<a name="line.61"></a>
<FONT color="green">062</FONT>             * If the class ultimately wasn't found a &lt;code&gt;ClassNotFoundException&lt;/code&gt; is being thrown. If class was found, but an error<a name="line.62"></a>
<FONT color="green">063</FONT>             * occurred, store exception for later review and return &lt;code&gt;null&lt;/code&gt;. This is done so because the overridden method can't throw an<a name="line.63"></a>
<FONT color="green">064</FONT>             * exception other than &lt;code&gt;ClassNotFoundException&lt;/code&gt;.<a name="line.64"></a>
<FONT color="green">065</FONT>             * <a name="line.65"></a>
<FONT color="green">066</FONT>             * @param className The path and name to the classfile.<a name="line.66"></a>
<FONT color="green">067</FONT>             * @return The requested class reference.<a name="line.67"></a>
<FONT color="green">068</FONT>             * @throws ClassNotFoundException<a name="line.68"></a>
<FONT color="green">069</FONT>             */<a name="line.69"></a>
<FONT color="green">070</FONT>            @Override<a name="line.70"></a>
<FONT color="green">071</FONT>            public final Class&lt;?&gt; findClass(final String className)<a name="line.71"></a>
<FONT color="green">072</FONT>                            throws ClassNotFoundException {<a name="line.72"></a>
<FONT color="green">073</FONT>                    exception = null;<a name="line.73"></a>
<FONT color="green">074</FONT>                    try {<a name="line.74"></a>
<FONT color="green">075</FONT>                            // try to load, cache and return the class from compiled .class file<a name="line.75"></a>
<FONT color="green">076</FONT>                            checkForFile(basepath, className);<a name="line.76"></a>
<FONT color="green">077</FONT>    <a name="line.77"></a>
<FONT color="green">078</FONT>                            // if a classfile is available then load it<a name="line.78"></a>
<FONT color="green">079</FONT>                            final Class&lt;?&gt; c = classes.get(className);<a name="line.79"></a>
<FONT color="green">080</FONT>                            if (c != null) {<a name="line.80"></a>
<FONT color="green">081</FONT>                                    return c;<a name="line.81"></a>
<FONT color="green">082</FONT>                            } else {<a name="line.82"></a>
<FONT color="green">083</FONT>                                    throw new ClassNotFoundException();<a name="line.83"></a>
<FONT color="green">084</FONT>                            }<a name="line.84"></a>
<FONT color="green">085</FONT>                    } catch (final ClassNotFoundException e) {<a name="line.85"></a>
<FONT color="green">086</FONT>                            // - see if class can be found in the VM<a name="line.86"></a>
<FONT color="green">087</FONT>                            // - this check must come last, else you won't detect whether a classfile has been recompiled<a name="line.87"></a>
<FONT color="green">088</FONT>                            final Class&lt;?&gt; c = findSystemClass(className);<a name="line.88"></a>
<FONT color="green">089</FONT>                            classes.put(className, c);<a name="line.89"></a>
<FONT color="green">090</FONT>                            return c;<a name="line.90"></a>
<FONT color="green">091</FONT>                    } catch (final IOException e) {<a name="line.91"></a>
<FONT color="green">092</FONT>                            exception = new CompileException(e.getMessage(), e);<a name="line.92"></a>
<FONT color="green">093</FONT>                            return null;<a name="line.93"></a>
<FONT color="green">094</FONT>                    } catch (final CompileException e) {<a name="line.94"></a>
<FONT color="green">095</FONT>                            exception = e;<a name="line.95"></a>
<FONT color="green">096</FONT>                            return null;<a name="line.96"></a>
<FONT color="green">097</FONT>                    }<a name="line.97"></a>
<FONT color="green">098</FONT>            }<a name="line.98"></a>
<FONT color="green">099</FONT>    <a name="line.99"></a>
<FONT color="green">100</FONT>            /**<a name="line.100"></a>
<FONT color="green">101</FONT>             * Reads and compiles the sourcefile from filesystem and creates the class inside the VM.<a name="line.101"></a>
<FONT color="green">102</FONT>             * <a name="line.102"></a>
<FONT color="green">103</FONT>             * @param className The path and name to the .java sourcefile.<a name="line.103"></a>
<FONT color="green">104</FONT>             * @throws CompileException<a name="line.104"></a>
<FONT color="green">105</FONT>             * @throws IOException<a name="line.105"></a>
<FONT color="green">106</FONT>             */<a name="line.106"></a>
<FONT color="green">107</FONT>            private void checkForFile(final String classPath, final String className)<a name="line.107"></a>
<FONT color="green">108</FONT>                            throws CompileException, IOException {<a name="line.108"></a>
<FONT color="green">109</FONT>                    // figure paths...<a name="line.109"></a>
<FONT color="green">110</FONT>                    final String resource = className.replace("..", "||").replace('.', File.separatorChar).replace("||", "..");<a name="line.110"></a>
<FONT color="green">111</FONT>                    final File javaSource = new File(classPath + File.separatorChar + resource + ".java");<a name="line.111"></a>
<FONT color="green">112</FONT>                    final File javaClass = new File(classPath + File.separatorChar + resource + ".class");<a name="line.112"></a>
<FONT color="green">113</FONT>    <a name="line.113"></a>
<FONT color="green">114</FONT>                    new File(basepath).getAbsolutePath();<a name="line.114"></a>
<FONT color="green">115</FONT>                    javaSource.getAbsolutePath();<a name="line.115"></a>
<FONT color="green">116</FONT>                    final String absoluteClassPath = javaClass.getAbsolutePath();<a name="line.116"></a>
<FONT color="green">117</FONT>    <a name="line.117"></a>
<FONT color="green">118</FONT>                    // see if there is a javafile and classfile<a name="line.118"></a>
<FONT color="green">119</FONT>                    if (javaSource.exists()) {<a name="line.119"></a>
<FONT color="green">120</FONT>                            // if classfile available, delete if outdated<a name="line.120"></a>
<FONT color="green">121</FONT>                            if (javaClass.exists()) {<a name="line.121"></a>
<FONT color="green">122</FONT>                                    // determine if the java sourcefile has been modified since last compile<a name="line.122"></a>
<FONT color="green">123</FONT>                                    // else check if the .class file has already been loaded<a name="line.123"></a>
<FONT color="green">124</FONT>                                    if (javaSource.lastModified() &gt; javaClass.lastModified()) {<a name="line.124"></a>
<FONT color="green">125</FONT>                                            if (!javaClass.delete()) {<a name="line.125"></a>
<FONT color="green">126</FONT>                                                    throw new CompileException("runtime compiler: unable to removed outdated .class file");<a name="line.126"></a>
<FONT color="green">127</FONT>                                            }<a name="line.127"></a>
<FONT color="green">128</FONT>                                            classes.remove(className);<a name="line.128"></a>
<FONT color="green">129</FONT>                                    } else if (classes.get(className) == null) {<a name="line.129"></a>
<FONT color="green">130</FONT>                                            classes.put(className, loadClass(absoluteClassPath, className));<a name="line.130"></a>
<FONT color="green">131</FONT>                                    }<a name="line.131"></a>
<FONT color="green">132</FONT>                            }<a name="line.132"></a>
<FONT color="green">133</FONT>    <a name="line.133"></a>
<FONT color="green">134</FONT>                            // if no classfile available or became outdated<a name="line.134"></a>
<FONT color="green">135</FONT>                            if (!javaClass.exists()) {<a name="line.135"></a>
<FONT color="green">136</FONT>                                    final int status = 0;// Main.compile(args);<a name="line.136"></a>
<FONT color="green">137</FONT>    <a name="line.137"></a>
<FONT color="green">138</FONT>                                    // load compiled classfile and cache it or return error that occured during compiling<a name="line.138"></a>
<FONT color="green">139</FONT>                                    switch (status) {<a name="line.139"></a>
<FONT color="green">140</FONT>                                    case 0:<a name="line.140"></a>
<FONT color="green">141</FONT>                                            classes.put(className, loadClass(absoluteClassPath, className));<a name="line.141"></a>
<FONT color="green">142</FONT>                                            break;<a name="line.142"></a>
<FONT color="green">143</FONT>                                    case 1:<a name="line.143"></a>
<FONT color="green">144</FONT>                                            throw new CompileException("runtime compiler: ERROR");<a name="line.144"></a>
<FONT color="green">145</FONT>                                    case 2:<a name="line.145"></a>
<FONT color="green">146</FONT>                                            throw new CompileException("runtime compiler: CMDERR");<a name="line.146"></a>
<FONT color="green">147</FONT>                                    case 3:<a name="line.147"></a>
<FONT color="green">148</FONT>                                            throw new CompileException("runtime compiler: SYSERR");<a name="line.148"></a>
<FONT color="green">149</FONT>                                    case 4:<a name="line.149"></a>
<FONT color="green">150</FONT>                                            throw new CompileException("runtime compiler: ABNORMAL");<a name="line.150"></a>
<FONT color="green">151</FONT>                                    default:<a name="line.151"></a>
<FONT color="green">152</FONT>                                            throw new CompileException("Compile status: Unknown exit status");<a name="line.152"></a>
<FONT color="green">153</FONT>                                    }<a name="line.153"></a>
<FONT color="green">154</FONT>                            }<a name="line.154"></a>
<FONT color="green">155</FONT>                    }<a name="line.155"></a>
<FONT color="green">156</FONT>            }<a name="line.156"></a>
<FONT color="green">157</FONT>    <a name="line.157"></a>
<FONT color="green">158</FONT>            /**<a name="line.158"></a>
<FONT color="green">159</FONT>             * Reads the classfile from filesystem.<a name="line.159"></a>
<FONT color="green">160</FONT>             * <a name="line.160"></a>
<FONT color="green">161</FONT>             * @param classPath The path and name to the classfile.<a name="line.161"></a>
<FONT color="green">162</FONT>             * @param className The name of the class to use as key for the Class reference value.<a name="line.162"></a>
<FONT color="green">163</FONT>             * @throws FileNotFoundException<a name="line.163"></a>
<FONT color="green">164</FONT>             * @throws IOException<a name="line.164"></a>
<FONT color="green">165</FONT>             */<a name="line.165"></a>
<FONT color="green">166</FONT>            private Class&lt;?&gt; loadClass(final String classPath, final String className)<a name="line.166"></a>
<FONT color="green">167</FONT>                            throws IOException {<a name="line.167"></a>
<FONT color="green">168</FONT>                    // get data from file<a name="line.168"></a>
<FONT color="green">169</FONT>                    final File f = new File(classPath);<a name="line.169"></a>
<FONT color="green">170</FONT>                    final int size = (int) f.length();<a name="line.170"></a>
<FONT color="green">171</FONT>                    final byte buff[] = new byte[size];<a name="line.171"></a>
<FONT color="green">172</FONT>                    final DataInputStream dis = new DataInputStream(new FileInputStream(f));<a name="line.172"></a>
<FONT color="green">173</FONT>                    dis.readFully(buff);<a name="line.173"></a>
<FONT color="green">174</FONT>                    dis.close();<a name="line.174"></a>
<FONT color="green">175</FONT>                    // convert data into class<a name="line.175"></a>
<FONT color="green">176</FONT>                    return defineClass(className, buff, 0, buff.length, null);<a name="line.176"></a>
<FONT color="green">177</FONT>            }<a name="line.177"></a>
<FONT color="green">178</FONT>    <a name="line.178"></a>
<FONT color="green">179</FONT>            /**<a name="line.179"></a>
<FONT color="green">180</FONT>             * Parameterized exception used when Java's runtime compiler fails to compile a Java source file.<a name="line.180"></a>
<FONT color="green">181</FONT>             * <a name="line.181"></a>
<FONT color="green">182</FONT>             * @author Benny Bottema<a name="line.182"></a>
<FONT color="green">183</FONT>             */<a name="line.183"></a>
<FONT color="green">184</FONT>            public static class CompileException extends ScriptException {<a name="line.184"></a>
<FONT color="green">185</FONT>                    private static final long serialVersionUID = -7210219718456902667L;<a name="line.185"></a>
<FONT color="green">186</FONT>    <a name="line.186"></a>
<FONT color="green">187</FONT>                    /**<a name="line.187"></a>
<FONT color="green">188</FONT>                     * @param reason The description of the cause of the exception.<a name="line.188"></a>
<FONT color="green">189</FONT>                     */<a name="line.189"></a>
<FONT color="green">190</FONT>                    public CompileException(final String reason) {<a name="line.190"></a>
<FONT color="green">191</FONT>                            super(reason);<a name="line.191"></a>
<FONT color="green">192</FONT>                    }<a name="line.192"></a>
<FONT color="green">193</FONT>    <a name="line.193"></a>
<FONT color="green">194</FONT>                    /**<a name="line.194"></a>
<FONT color="green">195</FONT>                     * Used to create an exception with a copies stacktrace (using {@link #setStackTrace(StackTraceElement[])}).<a name="line.195"></a>
<FONT color="green">196</FONT>                     * <a name="line.196"></a>
<FONT color="green">197</FONT>                     * @param reason The description of the cause of the exception.<a name="line.197"></a>
<FONT color="green">198</FONT>                     * @param cause A thrown exception that is the cause.<a name="line.198"></a>
<FONT color="green">199</FONT>                     */<a name="line.199"></a>
<FONT color="green">200</FONT>                    public CompileException(final String reason, final Throwable cause) {<a name="line.200"></a>
<FONT color="green">201</FONT>                            super(reason + "\n      " + cause.toString());<a name="line.201"></a>
<FONT color="green">202</FONT>                            setStackTrace(cause.getStackTrace());<a name="line.202"></a>
<FONT color="green">203</FONT>                    }<a name="line.203"></a>
<FONT color="green">204</FONT>            }<a name="line.204"></a>
<FONT color="green">205</FONT>    <a name="line.205"></a>
<FONT color="green">206</FONT>            /**<a name="line.206"></a>
<FONT color="green">207</FONT>             * Sets the base path this classloader will look for classes in.<a name="line.207"></a>
<FONT color="green">208</FONT>             * <a name="line.208"></a>
<FONT color="green">209</FONT>             * @param basepath A folder path to look for classes.<a name="line.209"></a>
<FONT color="green">210</FONT>             */<a name="line.210"></a>
<FONT color="green">211</FONT>            public void setBasepath(final String basepath) {<a name="line.211"></a>
<FONT color="green">212</FONT>                    this.basepath = basepath;<a name="line.212"></a>
<FONT color="green">213</FONT>            }<a name="line.213"></a>
<FONT color="green">214</FONT>    <a name="line.214"></a>
<FONT color="green">215</FONT>            /**<a name="line.215"></a>
<FONT color="green">216</FONT>             * @return {@link #basepath}<a name="line.216"></a>
<FONT color="green">217</FONT>             */<a name="line.217"></a>
<FONT color="green">218</FONT>            public String getBasepath() {<a name="line.218"></a>
<FONT color="green">219</FONT>                    return basepath;<a name="line.219"></a>
<FONT color="green">220</FONT>            }<a name="line.220"></a>
<FONT color="green">221</FONT>    }<a name="line.221"></a>




























































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